Earthing?

[JAZZCNC]

You can fit a braking resistor if the driver black box has provision for a braking resistor. A braking resistor dissipates unwanted energy and is one of the reasons a body might chose thicker wiring.

Exactly Clives point I think.!!! . . . There isn't a blood option for braking resistor on AM882 and tell the last time you or anyone else seen Nema 23 3Nm stepper motor fitted to Minimill using braking resisitor.!! . . . . . STOP TALKING SHIT.

[Edward]

Hahaha, this is getting interesting:)
In the EM806 and AM882 don't you have an over-current cut off with the red LED blinking? I think you really have to push them really hard, for instance, with high deceleration to get to that stage. I don't intend to drive this machine too madly:)
Also, I guess the psu will be able to cope with a bit of back EMF if I feel too adventurous...

Edward